The influence of Didecyldimethylammonium Chloride on the morphology and elemental composition of Staphylococcus aureus as determined by NanoSAM

Abstract

Didecyldimethylammonium chloride (DDAC) is a Quaternary Ammonium Compound (QAC) disinfectant often used in the poultry industry to disinfect hard surfaces. DDAC is a membrane active agent and causes the leakage of important intracellular material. Understanding the mode of action and possible resistance is important; in particular, the pending post antibiotic era that the poultry industry is facing. Staphylococcus aureus strain ATCC2357 treaded with DDAC revealed protruberances or bleb formations on their cell walls when observed with scanning electron microscopy. The DDAC treated cells were further investigated using NanoSAM. This technology showed morphological changes as well as structural detail on control cells caused by the disinfectant that scanning electron microscopy could not. NanoSAM also showed a decrease in the elemental intensities during the etching of the cells treated with QAC. This proved that QAC leads to the leakage of cellular material. Key words: Quaternary ammonium compound, Staphylococcus aureus, nano scanning electron microscopy.